xref: /linux/Documentation/devicetree/bindings/rtc/st,stm32-rtc.yaml (revision 566ab427f827b0256d3e8ce0235d088e6a9c28bd) 
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/rtc/st,stm32-rtc.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: STMicroelectronics STM32 Real Time Clock
8
9maintainers:
10  - Gabriel Fernandez <gabriel.fernandez@foss.st.com>
11
12properties:
13  compatible:
14    enum:
15      - st,stm32-rtc
16      - st,stm32h7-rtc
17      - st,stm32mp1-rtc
18      - st,stm32mp25-rtc
19
20  reg:
21    maxItems: 1
22
23  clocks:
24    minItems: 1
25    maxItems: 2
26
27  clock-names:
28    items:
29      - const: pclk
30      - const: rtc_ck
31
32  interrupts:
33    maxItems: 1
34
35  st,syscfg:
36    $ref: /schemas/types.yaml#/definitions/phandle-array
37    items:
38      minItems: 3
39      maxItems: 3
40    description: |
41      Phandle/offset/mask triplet. The phandle to pwrcfg used to
42      access control register at offset, and change the dbp (Disable Backup
43      Protection) bit represented by the mask, mandatory to disable/enable backup
44      domain (RTC registers) write protection.
45
46  assigned-clocks:
47    description: |
48      override default rtc_ck parent clock reference to the rtc_ck clock entry
49    maxItems: 1
50
51  assigned-clock-parents:
52    description: |
53      override default rtc_ck parent clock phandle of the new parent clock of rtc_ck
54    maxItems: 1
55
56patternProperties:
57  "^rtc-[a-z]+-[0-9]+$":
58    type: object
59    $ref: /schemas/pinctrl/pinmux-node.yaml
60    description: |
61      Configuration of STM32 RTC pins description. STM32 RTC is able to output
62      some signals on specific pins:
63      - LSCO (Low Speed Clock Output) that allow to output LSE clock on a pin.
64      - Alarm out that allow to send a pulse on a pin when alarm A of the RTC
65        expires.
66    additionalProperties: false
67    properties:
68      function:
69        enum:
70          - lsco
71          - alarm-a
72      pins:
73        enum:
74          - out1
75          - out2
76          - out2_rmp
77
78allOf:
79  - if:
80      properties:
81        compatible:
82          contains:
83            const: st,stm32-rtc
84
85    then:
86      properties:
87        clocks:
88          minItems: 1
89          maxItems: 1
90
91        clock-names: false
92
93      patternProperties:
94        "^rtc-[a-z]+-[0-9]+$": false
95
96      required:
97        - st,syscfg
98
99  - if:
100      properties:
101        compatible:
102          contains:
103            const: st,stm32h7-rtc
104
105    then:
106      properties:
107        clocks:
108          minItems: 2
109          maxItems: 2
110
111      patternProperties:
112        "^rtc-[a-z]+-[0-9]+$": false
113
114      required:
115        - clock-names
116        - st,syscfg
117
118  - if:
119      properties:
120        compatible:
121          contains:
122            enum:
123              - st,stm32mp1-rtc
124              - st,stm32mp25-rtc
125
126    then:
127      properties:
128        clocks:
129          minItems: 2
130          maxItems: 2
131
132        assigned-clocks: false
133        assigned-clock-parents: false
134
135      required:
136        - clock-names
137
138required:
139  - compatible
140  - reg
141  - clocks
142  - interrupts
143
144additionalProperties: false
145
146examples:
147  - |
148    #include <dt-bindings/mfd/stm32f4-rcc.h>
149    #include <dt-bindings/clock/stm32fx-clock.h>
150    rtc@40002800 {
151      compatible = "st,stm32-rtc";
152      reg = <0x40002800 0x400>;
153      clocks = <&rcc 1 CLK_RTC>;
154      assigned-clocks = <&rcc 1 CLK_RTC>;
155      assigned-clock-parents = <&rcc 1 CLK_LSE>;
156      interrupt-parent = <&exti>;
157      interrupts = <17 1>;
158      st,syscfg = <&pwrcfg 0x00 0x100>;
159    };
160
161  - |
162    #include <dt-bindings/interrupt-controller/arm-gic.h>
163    #include <dt-bindings/clock/stm32mp1-clks.h>
164    rtc@5c004000 {
165      compatible = "st,stm32mp1-rtc";
166      reg = <0x5c004000 0x400>;
167      clocks = <&rcc RTCAPB>, <&rcc RTC>;
168      clock-names = "pclk", "rtc_ck";
169      interrupts = <GIC_SPI 3 IRQ_TYPE_LEVEL_HIGH>;
170    };
171
172...
173